Instructions

The program
The program consists of two blocks. After clicking the green vane, an endless loop in the main program will wait for a button to be pushed.
Then the message roll is sent five times, each time calling the program block to display a random rolling result. The time intervals between the
rolled indications grow in length. This is what real dice look like when they come to a halt slowly.
23. Day
Christmas songs
The experiment of the 23rd day is a simple little piano that can be used to play five tones via putty contacts. The sixth contact, the ground line,
is only used when necessary.
Components: 1 x plug board, 5 x 20 MOhm resistor, 6 x
wire bridges (sensor contact), 7 x connection cables, 5 x
alligator clamp cable, 5 x putty contact
Of course, the Raspberry Pi can play any sounds. To be able to play music sensibly with the five available putty contacts, we use the pentatonic,
a scale that only has five tones - and the oldest historically documented scale, in use as early as in bone flutes from 3000 B.C.
Since the human brain is well able to remember five tones, the pentatonic scale with the notes C, D, E, G, A is often used in children's songs and
advertising music. A few examples:
Backe, backe, Kuchen (G-G-A-A-G-E)
Laterne, Laterne, Sonne, Mond und Sterne (A-G-E, A-G-E, G-G-A-A-G-E)
Old Mac Donald had a farm, hea hea ho! (C-C-C-G-A-A-G, E-E-D-D-C)
The program
An endless loop will query all five sensor contacts in sequence. When a sensor is touched, the corresponding note is output. The Raspberry Pi
can play music via an HDMI-monitor or an external speaker or headphones connected to the 3.5-mm jack plug socket.
If you don’t hear anything ...
... call
sudoraspi‐config
in an LXTerminal window and manually select the right
audio output in Advanced Options/Audio.